%0 Journal Article %1 Kaim.1990b %A Kaim, Wolfgang %A Kohlmann, Stephan. %D 1990 %J Inorganic Chemistry %K carbonyl charge configuration diimine dinuclear dinuclear;electrochem dinuclear;electron dinuclear;energy dinuclear;rhenium halo level redn rhenium transfer transition %N 16 %P 2909--2914 %R 10.1021/ic00341a010 %T The nature of reduced and excited states of p-electron-deficient complexes between tricarbonylhalorhenium and diimine ligands %V 29 %X (m-L)[Re(CO)3X]2 (X = Cl, Br) with the bridging bis-chelate ligands L = 2,2'-bipyrimidine, 2,5-bis(2-pyridyl)pyrazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, and 2,2'-azopyridine were synthesized. Coordination of 2 Re(CO)3X fragments causes a pronounced lowering of the ligand p* LUMOs, the dinuclear 2,2'-azopyridine complexes being reduced most easily at $\sim$+0.45 V vs. SCE. The resulting anion-radical complexes were characterized by ESR and, in part, by their visible absorption and CO vibrational spectra. ESR data data rule out a Re(0) or Re(0)/Re(I) formulation for the singly reduced monomers and dimers and show the spectral effect of X- loss for the labile mononuclear (bpy.bul.-)Re(CO)3Br (bpy = 2,2'-bipyridine). The well-sepd. long wavelength absorption bands from metal-ligand charge-transfer transitions of the most p-electron-deficient neutral complexes display a distinct structure. A comparison is made between the electronic structures of a-diimine complexes with W(CO)4, Re(CO)3X, and [Ru(bpy)2]2+ fragments. [on SciFinder(R)]

@article{Kaim.1990b, abstract = {(\textgreek{m}-L)[Re(CO)3X]2 (X = Cl, Br) with the bridging bis-chelate ligands L = 2,2'-bipyrimidine, 2,5-bis(2-pyridyl)pyrazine, 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, and 2,2'-azopyridine were synthesized. Coordination of 2 Re(CO)3X fragments causes a pronounced lowering of the ligand \textgreek{p}* LUMOs, the dinuclear 2,2'-azopyridine complexes being reduced most easily at $\sim$+0.45 V vs. SCE. The resulting anion-radical complexes were characterized by ESR and, in part, by their visible absorption and CO vibrational spectra. ESR data data rule out a Re(0) or Re(0)/Re(I) formulation for the singly reduced monomers and dimers and show the spectral effect of X- loss for the labile mononuclear (bpy.bul.-)Re(CO)3Br (bpy = 2,2'-bipyridine). The well-sepd. long wavelength absorption bands from metal-ligand charge-transfer transitions of the most \textgreek{p}-electron-deficient neutral complexes display a distinct structure. A comparison is made between the electronic structures of \textgreek{a}-diimine complexes with W(CO)4, Re(CO)3X, and [Ru(bpy)2]2+ fragments. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Kaim, Wolfgang and Kohlmann, Stephan.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/271be9a13d1bac7bbb84468cf3632ca31/huebleriac}, doi = {10.1021/ic00341a010}, interhash = {e919d727c76a5b1b5c6ff5cd97fdd842}, intrahash = {71be9a13d1bac7bbb84468cf3632ca31}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {carbonyl charge configuration diimine dinuclear dinuclear;electrochem dinuclear;electron dinuclear;energy dinuclear;rhenium halo level redn rhenium transfer transition}, number = 16, pages = {2909--2914}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {The nature of reduced and excited states of \textgreek{p}-electron-deficient complexes between tricarbonylhalorhenium and diimine ligands}, volume = 29, year = 1990 }